Friction latch for extension tables



April 21, 195s Z. W. MGCONNELL 2,635,934

FRICTION LATCH FOR EXTENSION TABLES Filed Aug. 23, 1952 GttornegPatented Apr. 21, 1953 UNITED STATES PATENT OFFICE Claims.

This invention relates to extension tables having relatively moveablesections and which refers more particularly to an improved latch forsecuring sections of the table against relative movement.

The principal object of the invention is to provide a friction latchconsisting of an inverted substantially U-shaped bracket Whose legs areprovided with lined apertures for the sliding reception of a rod havingone end supported by a bracket aixed on the under side of one of thetable sections adjacent the dividing line between the sections andopposite the U-shaped bracket which is attached on the under side of thecompanion table section. At least one of the legs of the U-shapedbracket is resilient to a certain degree and is disposed at an obtuseangle in relation to that portion of the bracket which is aflxed to thetable section s0 that in its normal angular position, the rod extendingthrough the aperture therein will be frictionally gripped and heldagainst longitudinal movement until the leg is displaced toward aposition perpendicular to the plane of the rod so that the latter may bereleased for free longitudinal movement to permit movement of the tablesections.

Another object of the invention is to provide a latch consisting of therod held at one end against other than rotative displacement andsupported intermediate its ends by the bracket having depending legs,provided with apertures through which the rod is capable of slidingdisplacement and in which one of the legs of the bracket is disposed atan angle in relation to the rod and to the companion leg of the bracketto frictionally engage the rod and hold the same against longitudinalmovement, together with means for changing the angular position of therod engaging leg of the bracket to free the rod for longitudinaldisplacement in the U-shaped bracket.

With the foregoing objects in view, the invention has further referenceto certain features of accomplishment which will become apparent as thedescription proceeds, taken in connection with the accompanying drawingswherein:

4 Figure 1 is a view of an extension table 4in longitudinal crosssection.

Figure 2 is a fragmentary sectional View of a table top on a largerscale showing the manner in which the friction latch is attached to theunder side of the table top sections and the manner in which thesections are displaced by the latch mechanism.

Figure 3 is a sectional view on a still larger scale taken o-n line 3-3of Figure 2.

Figure 4 is a view on yet :a larger scale showing a modified form of theinvention.

Figure 5 is a detailed perspective view of the friction element per seshown in Figure 4.

Figure 6 is a side elevational view of another modcation of theinvention, and

Figure 7 is a View in transverse section taken on line 'I-l of Figure 6.

Continuing with a more detailed description of the drawing, reference ismade primarily to Figure 1 in which reference numeral I0 denotesgenerally a conventional table having top sections I I and I2 which aremoveable in relation to each other for the incorporation of extensionleaves between the sections. To the undersides of the sections II and I2are afxed relatively sliding rails I3 of conventional design formaintaining rigidity between the sections in any position to which theymay be adjusted.

The present invention consists of an L-shaped bracket I4 which issecured by screws or other means I5 to the under side of the tablesection II adjacent the meeting point I6 of the table sections. In acorresponding position opposite the bracket I4, a substantially U-shapedbracket or friction latch Il is aflixed by screws or other means I8 tothe under side of the companion table top section I2. One leg I9 of thefriction latch I'I is perpendicular to the plane of the table section I2while the companion leg 20 of the latch is disposed at an obtuse anglein relation to the table top section I2 and to the plane of a rod 2|which extends through apertures 22 in aligned relationship in the legsI9 and 20 of the latch Il.

It is to be noted that that portion of the latch I'I which is affixed tothe under side of the table top section I2 is secured by the screws I8nearer the perpendicular leg I9 and that the unsecured portion of thelatch is curved slightly downwardly. By virture of this construction theangular leg 20 is possessed of greater resiliency than if that portionof the latch member I'I engaging the table top section I2 is secured atboth ends. Accordingly. the greater frictional force is brought to bearby the leg 20 on the rod 2| to .hold the latter against longitudinalmovement.

In order to release the rod 2| for free longitudinal displacement in theapertures of the legs I9 and 20 of the friction member I'I, the leg 20is required to be moved toward a position perpendicular to the plane ofthe rod 2 I. To accomplish this, a second and smaller rod 23 is arrangedabove and parallel with the rod 2| and extends through apertures 24 inthe legs I9 and 20 of the latch member Il. One end 25 of the rod 23 isbent slightly at a point spaced from its extremity in the manner shownin Figures 1 and 2 and at its opposite end there is provided a iingerloop 26 at right angles to the plane of the rod so that the rod 23 maybe rotated 180 to cause the leg 20 of the latch member I? to be moved inthe manner prescribed to relieve the rod 2l of frictional engagement bythe leg 23 to permit the table top sections H and l2 to be moved inrelation to each other.

The end of the rod 2i which extends through the bracket i4 is embracedby a short length of coil spring 21 and which spring is interposedbetween the depending leg of bracket i4 and a washer 23 which latter isheld on the rod by an enlarged head 29 formed on the end of the latter.On the opposite side of the leg of the bracket i4 is a protuberance 33formed on the rod 2i to limit the degree of movement of the rod inrelation to the bracket i4, which movement is under the control of aspring 21 and is provided so that maximum irictional restriction may beobtained between the bracket i4 and latch l1 to hold the table sectionsil and i2 securely together.

Referring now to Figures 4 and 5, an L- shaped bracket 3l is secured bymeans of screws or other means 32 to the under side of a table section33 adjacent the meeting point 34 between section 33 and the companiontable section 35. Secured by screws 33 to the under side of the tablesection 35 adjacent the meeting point 34 is a latch member 31. Thislatch member is in two parts. a stationary part 33 has a depending leg39 andwhose end opposite the leg 39 is bent in substantially U-shape at49, the upstanding end of the stationary portion 38, forming the leg ofthe U-shaped portion of 40 being formed by spaced apart legs 4I betweenwhich is disposed a moveable part 42. The moveable part 42 has a tailportion 43 which lies on the base of the U-shaped portion 49 of thestationary part 33 and is held thereon for slight tilting displacementby means of a. screw 44 passing through apertures in the base of portion40 of part 38 and an aperture in the portion 43 of part 42. The portion43 is biased by a coil spring 45Y surrounding the screw 44 intermediatethe portion 43 of part 42 and a nut 46 threaded on to the end screw 44.The part 42. has a leg 41 which is provided with, an aperture 48 inalignment with an aperture 49 in the leg 39. A rod 50 extends throughthe apertures 48 andV 49 and is held friotionally against longitudinalmovement by the angular position of the leg 41, under pressure imposedby the coil spring 45. That portion of the stationary partA 38 betweenthe upstanding legs 4i is bent downwardly to form a stop l against whichthe leg 41 of part 42 engages when it is moved towards the perpendicularposition to relieve friction-al tension on the rod 50. This isaccomplished manually by engaging the leg 41 with a finger to tiltl thepart 42 against the resistance of spring 45, while the rod 59 is engagedby the loop 52 and moved longitudinally to correspondingly move thetable top sections 33 and 35.

Embracing the innerv end of rod 59 is a coil spring 53, held in positionby a washer 54 and a cotter key 55. A cotter key 53 is shaped through atransverse aperture in the rod 59 on the side of the bracket 3i oppositethe side against which the spring 53 bears. This arrangement provideslimited longitudinal displacement of rod 50 to obtain maximum ofvfriction on the rod by the angular leg 41 of part 42 of the frictionlatch to hold the table sections ilrmly together.

Referring now to Figures 6 and 7 showing a further modified form of theinvention an L- shaped bracket 51 is secured by means of screws 58 tothe under side of a table top section 59 adjacent the meeting point 60between the section 59 and a companion section BI'. Adjacent the meetingpoint 93 a friction latch 52 is secured to the under side of tablesection 6l by means of screws 53. The latch member 62 is substantiallyinverted U -shape and the portion 34 thereof which is secured to thetable section 9i is free at one end and curved slightly downwardly tolend resiliency to the leg 65 which is disposed at an obtuse angle inrelation to aV rod 6B which extends through the lined apertures in theleg 55 and the perpendicular leg 31 of the latch member 52. The angularrelationship between leg 65 and the rod 59 imposes a frictional force onthe rod 66 in one. position of the latter, due to the fact that the, rod66 is attened longitudinally at diametrically opposite points 68 and 69,as revealed in Figure 7.

The rody 66 has a depending loop 19 on itsv outer end which provides ahandle for rotating and longitudinally moving the rod. When the ilatsides 68 and 69 are disposed on a horizontal plane as shown in Figure 7,the rod 66 may be. freely moved to displace theA table sections 59 and6i. However, when the handle 10 is moved or to a horizontal position todispose the at sides 53 and 59 in a vertical planev the rod isfrictionally engaged by the leg 65 of the latch member 62 and holds.the` table sections together or in adjusted positions by preventinglongitudinal displacement of the rod 86.

On the inner end of the rod B6 is mounted a coil spring 1i which is heldthereon by a. washer 12 and the enlarged head 13 of the rod. A cotterkey 14 is extended through the rod on the side of the bracket 51opposite the spring 1l. The spring 1ll provides for limited longitudinalmovement of the rod to oppose maximum friction on the latter to hold thetable sections firmly together.

It is understood that whileY the invention has been described asproviding afriction latch for the moveable sections of an extensiontable. it is clearly evident that the invention may be used whereversuch a friction latch may be applicable.

Manifestly,l the construction (and process) as,` shown and described iscapable of. some modiiication and such modification as may be construedto fall within the scope and meaning, of the appended claims is alsdconsidered to be within the spirit and intent of the invention.

What is claimed is:

1. A friction latch for relatively moveable members comprising a rod ina plane parallel with said members and secured at one end to one of saidmembers for limited longitudinal and rotative displacement, asubstantially U-shaped bracket defining a friction latch member affixedto the other of said relatively moveable members having alegperpendicular to the plane of said Y rod and a companion leg disposedatan obtuse a plane perpendicular to said rodto relieve friction betweensaid leg and/rod to releasethe latter for free longitudinal displacementto effect corresponding movement of said relatively moveable members.

2. A friction latch for a pair of members mounted for relativedisplacement, comprising a friction member of resilient material aixedadjacent one end to one of said moveable members and having a portioncurved away from said one of said members and having one end turned atright angles to the plane of said one of said members, a second legformed on the end of the curved portion of said latch member anddisposed at an obtuse angle in relation to the plane of said one of saidmembers, a bracket aflixed to the companion moveable member adjacent themeeting point between said members, a rod parallel with the plane ofsaid members and having one end mounted in said bracket for limitedlongitudinal and oscillative displacement, said rod extending throughaligned apertures in the legs of said friction member and held againstlongitudinal displacement by frictional engagement between said rod andthe obtuse angled leg of said friction member and means for changing theannular position of said obtuse angled leg in relation Ito said rod tofree said rod and said relatively moveable members for longitudinalmovement.

3. In a friction latch for relatively moveable members, a bracket xed toone of said relatively moveable members, a friction member affixed tothe other of said relatively moveable members, said friction memberhaving one leg at right angles to the plane of said relatively moveablemembers and the companion leg disposed at an obtuse angle in relation tothe plane of said relatively moveable members, said legs having alignedapertures, a rod extending through the apertures of said legs andjournaled at one end in said bracket for oscillative and limitedlongitudinal displacement and held against longitudinal displacement bythe annular relationship of said obtuse angled leg with said rod andmeans for displacing said obtuse angled leg towards a perpendicularplane withrespect to said rod to release the latter for freelongitudinal displacement and to eiTect corresponding displacementbetween said relatively moveable members.

4. The structure of claim 3 in which the latch member is secured onlyadjacent one end to a relatively moveable member and curved away fromsaid member to contribute resiliency to said opposite end of saidfriction member.

5. The structure of claim 3 in which the end of said rod journaled in`said bracket is embraced by a coil .sp-ring and held againstlongitudinal displacement to a degree permitted by said spring to imposemaximum frictional restraint on said rod to hold the relatively moveablemembers in secure juxtaposition.

ZACK W. MCC'ONNELT...

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date 687,431 Kimball Nov. 26, 1901 737,039 Stone Aug. 25, 1903774,046 Davis Nov.. 1, 1904 1,425,833 Bowers Aug. 15, 1922 1,508,190Ledbetter Sept. 9, 1924 2,588,174 Spielberg Mar. 4, 1952

